From the wreckage of a rematch that never was, Amir Khan moves on, hoping to fight again soon for the world titles that should never have been taken away from him, possibly against the rising young Philadelphian Danny García in late June or July.

Lamont Peterson, meanwhile, can only contemplate a desperate future, stripped not only of the titles he took from Khan last December when doped up on a testosterone pellet embedded in his hip (a mistake his camp ludicrously described as "inadvertent"), but destined to be regarded forever as a drug cheat and denied the chance to defend his belts against Khan in Las Vegas on 19 May.

That dream is shattered for the street kid rescued from poverty by a sport he would ultimately betray. He keeps the $500,000 (£309,200) he earned against Khan in Washington, but work opportunities are now seriously compromised.

He and his trainer, Barry Hunter, must go before the Nevada State Athletic Commission on Tuesday to hear what it makes of his excuse for testing positive for a synthetic steroid in March, but he knows the news will be grim. He has already been asked to hand back the light-welterweight belts of the International Boxing Federation and the World Boxing Association, and faces the prospect of a lengthy exclusion from the only job he has ever known. The IBF said it intends to speak to Peterson over the coming days.

Khan feels some sympathy for him, but anger and frustration drown out all other emotions. When his American partner, Golden Boy Promotions, told him late on Wednesday evening they were going to take a $250,000 (£155,000) hit and cancel the show at the Mandalay Bay (HBO will drop $1m), Khan was already resigned to the disappointment. You would not have known that from the venom with which he pounded the bag, or the sweat he worked up on the speed ball – even though he knew he had no fight to train for. But he was still in "fight mode", still pumped up – on natural adrenaline.

"It would have been good if they had told us earlier this was going on," he said of the communication relayed to his camp only last Monday – even though Peterson failed his drug test on 19 March, with the result confirmed within a fortnight. "We could have had a replacement, but it's too late now. Two weeks away from the fight, I have peaked, done all the hard work in the Philippines. I'm in the best shape I could ever be in."

Khan feels vindicated, though. He was widely criticised for complaining about the result in the first fight, labelled a bad sport and a whinger. Those who needed little excuse to pour scorn on him did so with glee. They will be a little quieter this morning.

"Don't get me wrong. He's a nice guy. He's very humble, quiet. I met him a few times before we fought. But there was something there in that fight, that I couldn't get over. There was the judging that wasn't right, for a start, the points taken off me by the referee, and why was that guy [the infamous 'Cat in the Hat'] sat there at ringside? There was something going on there, man. I had to make an issue of it because if I didn't people would have said: 'Look, he got beat,' and I knew I didn't lose that fight fair and square."

Khan said he was stunned by Peterson's strength. "He could have destroyed my career. If I wasn't fit and strong and had the boxing skills … I might never have been the same again. It was back and forth, we were both hitting the other so hard, even though I wasn't hurt.

"He was so strong. Now we know why. I've seen him fight numerous times but when I was hitting him, he just wasn't going back. [Marcos] Maidana, I hit him and he went back, Zab Judah too. I hit hard for a light-welterweight. After the first round, when he was down twice, I thought: 'Not many fighters would get up from that.' But he recovered so quickly.

"In the ninth round he got caught with another good shot, then I hit him with another good combination and I just couldn't finish him. If he wasn't on anything I think I would have knocked him out in that fight.

"In rounds 10 and 11, he was running from one corner to the other corner, because I was moving away from him – and that's what testosterone does to you. It gives you that fire. Previous fights, he's never fought like that.

"That's why I was looking forward to this rematch more than any other fight. My dad said: 'I hear he's tested positive,' but I said: 'I'll still go in there and fight him, because, even if he is on drugs, I will still beat him.' But my dad wouldn't let me do it. He said: 'Look, at the end of the day, your health means more.' He's right."

Peterson's publicist Andre Johnson has again insisted that the 28-year-old has done nothing wrong, telling Sky: "He has been boxing for 18 years. In 18 years, barring this incident, he's never tested positive for anything – and after this incident three other tests were taken that he tested negative for.

"We're going to get to the bottom of this and do everything in our power to clear Lamont's name. Lamont will be fighting very soon. We're extremely disappointed. We wanted to make this fight happen. We're sorry it didn't happen. Lamont did nothing wrong. He's not a doper. He's not a cheater." A later statement from Peterson team said: "Once all the facts have been reviewed we have no doubt that he will be vindicated."

But despite the denials, what respect there was between the fighters has vanished over the past couple of days. "How could he act so innocent to begin with?" Khan asked. "He could have destroyed my life. How can I respect someone like Lamont Peterson now, when he didn't respect my life? And he doesn't respect the sport. I hope he does get punished.

"He has just destroyed his whole legacy. I think he's done now. You know, he made a lot of money in the last fight, about four or five hundred grand; this fight he was making $1.6m, which was by far his biggest payday – and he's not going to get that sort of money any more. It would have changed his life."